I tend to do both. Crimp with a good tool, mines a Klein but any with an arch and a tooth give a positive crimp. These are used where there is no water, oil, or other contaminant like under the dash and I solder ones exposed like gas gauges, brake lights, and any where stuff could work it's way into a crimp only. A test is to clamp a crimped terminal into a vise and pull wire till it breaks. If wire stub is still in terminal you have a good crimping tool.
